On Tue, 16 Jun 2015 18:53:51 +1000 Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> On 06/16/2015 03:28 AM, Greg Kurz wrote: > > According to PAPR+ 3.2.2.2, the TCE is implemented as follows: > > bits 0-51: real page number > > bits 52-61: reserved for future use > > bits 62-63: page protection (read-only, write-only, read-write) > > > > tce_list is not a TCE, it is "The logical address of a page of (4 K long on > a 4 K boundary) of TCE contents to be stored in the TCE table (contains > logical address of storage page to be mapped)" so we rather want to remove > (tce_list & ~SPAPR_TCE_RW) below. > Oops my bad for the confustion... :-\ Then it looks like SPAPR_TCE_RW can be dropped as well since put_tce_emu() uses IOMMU_RW instead. > > > Possible values for the protection bits are necessarly non-zero and thus > > H_PUT_TCE_INDIRECT currently always fails and returns H_PARAMETER. > > > > The code explicitly clears the protection bits when computing the TCE > > offset, > > a few lines below (tce_list & ~SPAPR_TCE_RW)... The sanity check is > > obviously > > wrong for these bits. > > > > Moreover, I could find no indication in PAPR+ that using the other reserved > > bits should error out with H_PARAMETER. > > > > This patch simply drops the offending check. > > > > Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com> > > --- > > hw/ppc/spapr_iommu.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c > > index 8cd9dba9ac4d..37a1110c9d87 100644 > > --- a/hw/ppc/spapr_iommu.c > > +++ b/hw/ppc/spapr_iommu.c > > @@ -258,7 +258,7 @@ static target_ulong h_put_tce_indirect(PowerPCCPU *cpu, > > return H_PARAMETER; > > } > > > > - if ((npages > 512) || (tce_list & SPAPR_TCE_PAGE_MASK)) { > > + if (npages > 512) { > > return H_PARAMETER; > > } > > > > > > > >